public class E4_20{
    public static void main(String s[]){
	char [] a = {'a','b','c','D','E','F'};
	for(int i= 0;i<a.length;i++){
	  if(Character.isLowerCase(a[i]))
	     a[i]= Character.toUpperCase(a[i]);
	  else if(Character.isUpperCase(a[i]))
	     a[i]= Character.toLowerCase(a[i]);
        }
        for(int i=0;i<a.length;i++)
	  System.out.println(""+a[i]);
    }
}